The effectiveness of fighter aircraft today is a function not only of the plane, but of the ability of the pilot to withstand the g-loads created by aircraft manuevering. When the pilot is subjected to high accelerations, his blood drains from his head and "pools" into his lower extremities, causing dizziness, unconsciousness and possible death. Recent attempts to provide anti-g protection are shown in Beaussant, U.S. Pat. No. 4,546,491; Beaussant et al., U.S. Pat. No. 4,230,097, Crosbie et al., U.S. Pat. No. 4,243,024; Crosbie et al., U.S. Pat. No. 4,534,338; Krough et al., U.S. Pat. No. 4,638,791; Van Patten, U.S. Pat. No. 4,736,731; Aviation Week And Space Technology, "USAF to Test Tactical Life Support System", Oct. 20, 1986, pg. 77, which use air inflated trousers and an elaborate system of valves and electronic valve inputs to pressurize the suit. McGrady et al., U.S. Pat. No. 4,787,576 shows a seat that is capable of reclining, positioning the pilot normal to the direction of acceleration, preventing the pooling of blood. The response time of these devices is inadequate in the initial stages of acceleration, since the pilot can lose consciousness during the period that his suit inflates or the seat reclines. Additionally, these suits are only effective up to 8 g's, wherein present aircraft are capable of sustaining 12 g's. A "g" as used herein, denotes a unit of acceleration equal to 32.2 feet per second per second, or 9.81 meters per second per second. Thus there is need for a simple, anti-g suit that instantaneously responds to aircraft rapid onset accelerations up to at least 12 g's.
As shown in Holste, U.S. Pat. No. Re 22,101; Beall, U.S. Pat. No. 2,335,474; Gray, U.S. Pat. No. 3,089,482; Kops et al., U.S. Pat. No. 3,124,123; Gongwer, U.S. Pat. No. 3,137,290; it has long been known that surrounding the body with a fluid will counteract the g-load effect. When subjected to acceleration, the fluid exerts a hydrostatic pressure on the user's body, squeezing the lower extremities and preventing the blood from "pooling". The fluid also squeezes the user's chest making it difficult to inhale. The increased fluid pressure on the chest, can be offset by providing the user with pressurized breathing gases which help counteract the fluid pressure on the chest wall. In most aircraft, pressurized gases are supplied to the user when the aircraft reaches a predetermined altitude. These systems are inadequate for g-protection because they are responsive to ambient pressure and not g-forces. If the user is at low altitude and is subjected to g-loads, no pressurized breathing is provided to overcome the increased hydrostatic fluid pressure. Providing a constant supply of pressurized gases is also inadequate. For example, if the gas pressure is set to overcome fluid pressure at 4 g's, it would provide too much pressure at 1 g, making it difficult for the user to exhale. Therefore, there is a need for a fluid filled g-suit having a regulator that supplies, and instantaneously changes the pressure of breathing gases supplied to the user, as a function of acceleration and ambient pressure.
Regulators as shown in Seireg et al., U.S. Pat. No. 4,289,126; Wetzel et al., U.S. Pat. No. 4,676,238; Christianson, U.S. Pat. No. Re 31,932, are used in underwater breathing apparatuses, and provide increased air pressure, as the diver descends and the water pressure increases. Heretofore, such regulators have not been integrated into a g-suit and have not been made responsive to acceleration.
A pilot is subjected to various hostile environments, such as temperature extremes, radiation bombardment, and biological and chemical contaminants. Protective body suits, incorporating heat exchangers are old in the art as shown in Parker et al., U.S. Pat. No. 3,744,053; Wiswell, U.S. Pat. No. 3,391,405; Curtis, U.S. Pat. No. 3,635,216; Chambers et al., U.S. Pat. No. 3,736,764, but there has yet to be a fluid filled g-suit, wherein the fluid provides radiation, chemical and or biological protection in addition to temperature control.
In summary there has never been a g-suit which can be an integrated self-sufficient unit, that allows a user to work in comfort, while subjected to acceleration, high altitudes, extreme temperatures, and hostile radiation, biological and chemical environments.